It works using 4G signals that can deliver speeds of up to 65Mbps, according to UK Broadband.

The only other way businesses and homes can get fibre-speed broadband without a landline connection is through Virgin Media's cable broadband service, which does not require an active ADSL connection, saving customers the need to pay for line rental.

Unlike BT, Sky and other broadband providers, Virgin Media can offer landline-free broadband because it doesn't use an Asymmetrical Digital Subscriber Line (ADSL), which must be active for most broadband services to work.

UK Broadband added that Relish users will also benefit from unlimited data allowances and a consistent performance, even at peak times. Furthermore, Relish can be set up without an engineer and month-to-month rolling contracts are likely to appeal to renters, students or pop-up businesses that are likely to move often.

“Central London is home to some of the world’s most talented and busy people, who have to suffer long delays in getting their broadband service set up and pay a ‘landline tax’ for a service they often don’t need,” said UK Broadband CEO Nicholas James.

“Relish wants to give Londoners the broadband they deserve – and will shake up the market with a fair and transparent service that meets the digital demands of modern Londoners.”

Relish will be competing with several other companies who also offer 4G mobile broadband through dongles and Mi-Fi devices. However, what differentiates Relish from its competitors is the price.

Home broadband deals start from £20 a month and come with a Huawei-manufactured router that can connect up to 25 devices. Businesses can get the same for £25 a month if they commit to a 12-month contract.

The service is limited to central London at present, ranging from Kensington in the west to Canary Wharf in the east, but there is little coverage south of the River Thames.

UK Broadband said it plans to expand coverage across Greater London and out to other UK towns and cities in the future.